Vapor-dispensing systems are employed to dispense vapors into a particular environment and include both passive systems, whereby the vapor is dispensed by stagnant diffusion and/or random air circulation over the surface of a vapor dispenser, and active systems which involve a forced air flow over the dispenser. Vapor dispensers may be employed for dispensing a variety of vapors into an environment, including medicinal vapors, odor counteractants, pheromones, insect repellents, pesticides, and perservatives, but more particularly are directed to air-freshening dispensers and systems wherein a volatile fragrance is vaporized from the dispenser into the environment over a desired period of time with a desired threshold or intensity level.
Standard air-freshener delivery dispensers and systems presently include such static-type systems as cans of a liquid to be dispensed which include a wick as a dispensing surface, aqueous gels containing an active-fragrance ingredient, and sponges, waxes, blotting papers and the like containing or treated with a fragrance. Active systems include dispenser-type containers wherein a vehicle-containing fragrance, either in gel, liquid or other form, is dispensed into the atmosphere by passing air over the fragrance-dispensing surface of the vehicle by the use of a battery- or power-driven fan.
Present commercial vapor-dispensing products and systems are not wholly satisfactory in that they include one or more disadvantages, such as being inconvenient for incorporation into the dispensing systems; providing nonuniform or uncontrolled release; being bulky or heavy; using a highly dilute fragrance-emission vehicle; holding only a very limited fragrance payload based on their size or weight; needing to be manually altered during use to obtain a near uniform fragrance release; retaining at the end of their effective or desired lifetime a large portion of the volatile fragrance within their structure; unstorable for extended periods of time without redistribution of the fragrance or other internal liquid; leaking when the vapor-dispensing package is damaged, shaken, inverted or unsatisfactorily packaged; being uneconomical for manufacture and distribution; and having an undesirably short or long lifetime.
It is, therefore, desirable to provide a simple, economical, easily manufactured, controlled-release vapor-dispenser produce and method of preparing the same, which will overcome one or more of the disadvantages of the present commercial vapor-dispenser products. It is recognized that it is a part of the prior art to load a volatile fragrance into a porous material, such as felt, blotting paper, sponge, etc., to provide a surface for the emission of vapor into the environment; that is, as a space air-freshener product. However, such products are not wholly satisfactory in use or performance, since there is poor or no control of the release rate of the fragrance over the desired time release span. In addition, attempts to incorporate a high volumetric amount of the liquid into the porous material often create leakage and drainage problems which are unsightly and often damage contiguous surfaces. Therefore, such products typically have an unsatisfactory performance life and/or nonuniform and unsatisfactory performance properties.